In this study, partially stabilized zirconia was synthesized using a chemical $Y_2O_3$ stabilizer and hydrothermal method. First, $YCl_3-6H_2O$ and $ZrCl_2O-8H_2O$ was dissolved in distilled water. Y-TZP (a $Y_2O_3$-doped toughened zirconia polycrystalline precursor) was also prepared by conventional co-precipitates in the presence of an excess amount of $NH_4OH$ solution under a fixed pH of 12. The Y-TZP precursors were filtered and repeatedly washed with distilled water to remove $Cl^-$ ions. $ZrO_2$-Xmol%$Y_2O_3$ powder was synthesized by a hydrothermal method using Teflon Vessels at $180^{circ}C$ for 6 h of optimized condition. The powder added with the Xmol%- $Y_2O_3$ (X = 0,1,3,5 mol%) stabilizer of the $ZrO_2$ was synthesized. The crystal phase, particle size, and morphologies were analyzed. Rectangular specimens of $33mm{ imes}8mm{ imes}3$ mm for three-point bend tests were used in the mechanical properties evaluation. A teragonal phase was observed in the samples, which contains more than 3 mol% $Y_2O_3$. The $3Y-ZrO_2$ agglomerated particle size was measured at $7.01{mu}m$. The agglomerated particle was clearly observed in the sample of 5 mol % $Y_2O_3-ZrO_2$, and and the agglomerated particle size was measured at 16.4 um. However, a 20 nm particle was specifically observed by FE-SEM in the sample of 3 mol% $Y_2O_3-ZrO_2$. The highest bending fracture strength was measured as 321.3 MPa in sample of 3 mol% $Y_2O_3-ZrO_2$.